Rotary engine



(No Model.) 2 Sheets-Sheet 2.

N. WITTS.

ROTARY ENGINE.

N0.587,904. 1 Patented Aug.1o,1897.

UNITED STATES PATENT QEEICE.

NELSONVITTS, OF' ALMA CITY, MINNESOTA.

ROTARY ENGINE.

SPECIFICATIONforming part of Letters Patent No. 587,904, dated August l0, 1897.

Application filed January 13, 1897. Serial No. 6191075- (NO mOdSL) To LZZ whom t 711m/ concern.-

Be it known that I, NELSON VITTS, a citizen of the United States, residing at Alma City, county of Vaseca, and State of Minnesota, have invented certain new and useful Improvements in Rotary Engines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference bein g had to the accompanying'drawings, and to letters and figures of reference marked thereon, which form a part of this specification.

This invention relates to rotary engines, and more particularly to that class in which a revoluble diskvhaving radially-movable pistons is used; and it has for its object certain improvements whereby the construction is materially simplified and cheapened and the dimensions relatively to a given power considerably reduced.

In the accompanying drawings, Figure 1 is a side elevation of my improved engine, one of the heads being removed. Figs. 2 and 3 are'like .views of the two heads. Fig. i is a transverse section of the engine, taken on line :c cc of Fig. 1, as it appears when looking in the direction of arrows a," 5c', said section being shown to an enlarged scale; and Fig. 5 is a perspective view of one of the radially-movable pistons.

The engine consists, essentially, of two heads, a piston-disk arranged between such heads and having radially-movable pistons, a shaft to which the piston-disk is secured, and means for supplying the motive iiuid to and for exhausting the same from the engine.

The head or head-plate H has an opening o, Fig. 2, for the engine-shaft and a segmental stepped portion h h2, whose inner faces are arcs of a circle having for center the center of the shaft-opening o. To the upper face of the higher portion h2 of the stepped sector and to a ledge h', extending along the lower edge of the head H, is bolted fluid-tight the other head, H', in the inner face of which is formed an irregular or cam groove h3. The remaining portion of the head H may be constructed, as shown in Figs. 1 and 2, with a hub portion h* and radial spokes h5, While the head H is preferably made solid. Between these heads H and H works the piston-disk P, which is secured to the engine-shaft S, that revolves freely in the opening o of head H and in a corresponding opening o in head H". The piston-diskP is provided with a number of radially-arranged pistons p, that carry at their inner ends an antifriction-roller r, projecting into the aforesaid cam-groove h3 in head H'. The piston-disk P is of such diameter relatively to the segmental raised portion h2 on the head H as to leave a space s between the periphery of said disk and the inner arcuate face of the raised portion h2, as shown more plainly in Fig. l, except at the lower end, where said portion h2 is extended inwardly into contact with the periphery of the disk P, as shown, to form an end Wall 2 for said space s.

As shown in Figs. l and 2, the raised portion h2 is recessed from' its.inwardly-projecting end 2 to a point 3, whereby the inner portion 4 of the space s is enlarged for purposes hereinafter referred to, the motive-fluid admission-pipe 4X being arranged to extend through said inwardly-extended portion 2. The cam-groove h3 is of such a form as to project the pistons p from the disk P the moment said pistons have cleared the end wall 2 of the space s, in which position they remain until they reach or are about to reach the opposite end in of said space, when said arms are again retracted iiush with the periphery of the disk P. It will thus be seen that the outer weighted end p of the pistons p during the time they a're projected and as soon as they reach the point- 3 of the aforesaid space s form, with the end wall 2, a closed 'motive-fluid chamber, the inner portion 4 of which is enlarged. enlargingthe inner end of the motive-fluid space s is to avoid back pressure upon the projected end p of a piston-arm p after entering the motive-fluid passage s, the pressure within the enlarged part 4 of said space acting equally upon all sides of the projected end p of the piston whether the motive duidas steam, water, or air-is admitted to the enlarged portion 1i of the space through the The obj ect of IOO end wall 2 thereof or at any other point of said enlarged portion, as will be readily understood.

In the described construction of engine the motive iiuid acts at all times upon a single piston p to revolve the disk Pand therethrough the shaft S, and before the piston has cleared the outer space s the next succeeding piston will have reached the point 3 or outer end of the enlarged portion of said space, so that when the preceding piston clears` the space s the motive iuid between the two will exhaust.

In order to avoid the noise due to the sudden liberation of steam, for instance, confined between two pistons in the narrower portion of the space s, I prefer to form an exhaust-channel 8, as shown in dotted lines in Fig. l, in the vertical face of the raised portion h2, the depth 'of which channel is gradually increased outwardly to the outer end of such vertical face or to the outer end 4f of space s, .whereby the motive fluid is gradually exhausted.

The piston-disk works, of course, fluidtight between the raised portion h2 of the segmental stepped portion on head II and between the inner face of head II', while the outer winged end p' Vof the pistons p works iiuid-tight along the under face of the raised portion h2 of said stepped portion and between the inner faces of the head H' and raised portion h of head II.

In the drawings I have shown the pistondisk P constructed in the form of a wheel, and with the open construction of the head II a very light though very powerful engine is obtained. Y

Inasmuch as the rotation of the piston-disk P cannot be reversed it will be necessary to provide two engines on the same shaft, their arrangement thereon being reversed, of course, whenever it is desirable vto reverse the direction of rotation of such shaft. On the other hand, instead of exhausting the motive fluid directly into the atmosphere, suitable means may be provided at the exhaust end 4a of the motive-duid space s to catch the exhausted motive fluid and conduct it to a point distant from the engine. In this case the upper half of the head-plate H proper Y may be made solid and the exhaust taken through a suitable opening therein at or s, which end would of course be closed or merge into an exhaust-chamber.

It will be seen that the alternate projection and retraction of the pistons p is effected positively or mechanically by the cam-groove h3 and not by means of motive uid, as has heretofore been proposed, thereby rendering their operation more certain. On the other hand, the actual motive-Huid space is of a very limited area, so that the expense of truing the surfaces to fit or work Huid-tight is greatly reduced, while the packing of the engine-shaft is entirely dispensed with, thereby doing away with a great deal of friction.

The piston-disk P is properly supported on the shaft S, between the heads II and H', by providing said disk with a suitably-enlarged hub p2, fitting snugly between the said heads.

The engine may be secured in any desired manner to a floor or other foundation, i to which end the heads II and H may be pro- Vided with foot-flanges, as shown in Fig. 4.

Having thus described my invent-ion, what I claim as new therein, and desire to secure by Letters Patent, is-

A rotary engine comprised of two headplates, II, II', the head II being constructed with a hub portion having segmental spokes and a segmental stepped portion whose inner faces arearcs of a circle having for center a shaft-opening formed in said hub, a ledge formed on the lower edge of the head, the head H' bolted to said ledge and segmental stepped portion forming a fluid-space beneath the stepped portion, a cam and a shaft-bearing formed in said head, a shaft revoluble in said bearings, a piston-disk on the shaft between said heads, pistons movablein said disk, arms on the pistons carrying antifriction-rollers working in the cam-groove whereby said pistons are projected into the fluid-chamber on entering and withdrawn upon leaving the :proximate to the exhaust end 4 of the space chamber, substantially as and for the purpose NELSON WIITS.

W'itnesses:

B. S. OBER, HENRY ORTH, Jr. 

